As the demand for diesel boiling range fuel increases worldwide there is increasing interest in sources other than petroleum crude oil for producing diesel fuel and diesel fuel blending components. One such renewable source is what has been termed biorenewable sources. These renewable sources include, but are not limited to, plant oils such as corn, rapeseed, canola, soybean and algal oils, animal fats such as inedible tallow, fish oils and various waste streams such as yellow and brown greases and sewage sludge. The common feature of these sources is that they are composed of glycerides and Free Fatty Acids (FFA). Both of these classes of compounds contain n-aliphatic carbon chains having from about 8 to about 24 carbon atoms. The aliphatic carbon chains in the glycerides or FFAs can be fully saturated or mono, di- or poly-unsaturated.
There are reports in the art disclosing the production of hydrocarbons from oils. For example, U.S. Pat. No. 4,300,009 discloses the use of crystalline aluminosilicate zeolites to convert plant oils such as corn oil to hydrocarbons such as gasoline and chemicals such as paraxylene. U.S. Pat. No. 4,992,605 discloses the production of hydrocarbon products in the diesel boiling range by hydroprocessing vegetable oils such as canola or sunflower oil. Finally, US 2004/0230085 A1 discloses a process for treating a hydrocarbon component of biological origin by hydrodeoxygenation followed by isomerization.
Disclosed herein is a process which comprises one or more steps to hydrogenate, deoxygenate and isomerize the renewable feedstock. The temperature in the hydrogenation and deoxygenation zones is controlled using a non-flashing liquid quench which is introduced counter current to the flow of reactants and products in the hydrogenation and deoxygenation zone.